Starches containing non-ionic, basic and acidic groups and preparation and uses thereof

ABSTRACT

Starches, especially high amylose starches containing nonionic, basic (cationic) and acidic (anionic) groups, preferably hydroxyalkylether (non-ionic), tertiary amino, cyanamide or quaternary amino (cationic) and sulfonic acid or sulfonate groups or carboxylic or carboxylate, or phosphate or phosphonate (anionic), in the starch molecule, are prepared which are especially useful for sizing threads or yarns of mixed fibers such as, for example, cotton fibers and polyester fibers, viz., polyethylene terephthalate fibers, and hydrophobic fibers that are difficult to size.

United States Patent Elizer [151 3,673,171 June 27, 1972 [54] STARCIIES CONTAINING NON-IONIC, BASIC AND ACIDIC GROUPS AND PREPARATION AND USES THEREOF [72] Inventor: Lee H. Elizer, Keokuk, Iowa [73] Assignee: The I-lubinger Company, Keokuk, Iowa [22] Filed: July 28, I970 [21] Appl. No.: 58,988 v Related US. Application Data [63] Continuation-impart of Ser. No. 733,233, May 31,

I968, abandon ed.

A [52] A US. Cl. ..260/233.3 R, 106/213, ll7/I39.5 C,

, 260/2335 [51] Int. Cl., ..C08b 19/01 [58] Field of Search 260/2333, 233.5

[56 References Cited UNITED STATES PATENTS 3,467,647 9/1969 Benninga ..260/209 3,459,632 8/1969 Caldwelletal. ..162/l75 3,046,272 7/1962 Stratingetal... ..260/233.3

3,051,700 8/1962 Elizeretal ..260/233.3

Primary Examiner-M. 1. Welsh Assistant Examiner-M. l. Marquis Attorney-Johnston, Root, O'Keeffe, Keil, Thompson and Shurtleff [57] ABSTRACT 13 Claims, No Drawings STARCI'IES CONTAINING NON-IONIC, BASIC AND ACIDIC GROUPS AND PREPARATION AND USES THEREOF This application is a continuation-in-part of United States application Ser. No. 733,233 filed May 31, 1968, now abandoned.

BACKGROUND OF THE INVENTION Starches in general are composed of two different types of polysaccharides, amylose and amylopectin. Both are composed of D-glycopyranose residues. Amylose is a linear molecule, whereas amylopectin has a branch chain molecular structure.

Formation of smooth gels of high amylose content starches, i.e., containing about 50 percent or more amylose, requires autoclaving under pressure. The inconvenience and costs occasioned thereby often makes the use of such starches economically unfeasible. Furthermore, the starch pastes, after gelatinization under pressure, tend to be unstable because of the tendency of the high amylose starch to separate from the water of gelation.

It is well known that starches are useful in sizing cotton fibers and for a wide variety of other industrial purposes. In recent years, many synthetic fibers have become available, and it has been difficult to find relatively inexpensive sizing compositions which are suitable for sizing a wide variety of these fibers,including mixtures of cotton and synthetic fibers. In particular, it has been difficult to provide suitable low cost sizing compositions for mixtures of polyester fibers and cotton. In common practice, the fibers are sized in the form of threads or yarns prior to weaving. The sized threads or yarns are then woven into cloth and thereafter the sizing material is removed by washing with water containing detergent or by treatment with enzymes. A satisfactory sizing composition is one which will provide suitable lubrication and resistance during weaving and at the same time can be readily removed thereafter.

One of the objects of the present invention is to provide new and improved starch products which are especially useful in textile sizing and can be employed for a wide variety of other purposes.

Another object of the invention is to provide new and improved starch products which can be employed effectively in sizing the more hydrophobic textile fibers, and mixtures of such fibers with other fibers, which have heretofore been very difficult to size.

An additional object of the invention is to produce new and improved starch products on an economically sound basis.

Still a further object of the invention is to provide a new and improved process for producing starch products having new and useful properties. Other objects will appear hereinafter.

THE INVENTION The present invention is concerned with the modification of starches and especially high amylose starches by chemically combining said starches through oxygen atoms of the polysaccharide molecules with hydroxyalkyl groups or hydroxyalkylether groups, basic and acidic groups. The added groups or substituents provide a starch composition containing non-ionic, anionic and cationic groups. These new and improved starch products are prepared by reacting an ungelatinized starch, preferably a high amylose starch containing about 50 percent or more amylose, with an alkylene oxide (e.g., ethylene oxide, 1,2-propylene oxide and/or l,2-butylene oxide), a nitrogen containing etherifying agent and also with a sultone. The preferred alkylene oxide is ethylene oxide, or l,2 propylene oxide, or mixtures of ethylene oxide and 1,2- propylene oxide, or l,2-propylene oxide followed by ethylene oxide. The preferred nitrogen containing etherifying agent is a dialkylchloroalkyl tertiary amine in the form of its hydrochloride salt such as 2-chloroethyldiethylamine hydrochloride, and the preferred sultone is propane sultone or butane sultone.

Ethylene oxide has the formula:

The 1,2-propylene oxide has the formula:

The 2-chloroethyldiethylamine hydrochloride (also called 2-chloro-N,N-diethylethylarnine hydrochloride) has the for mula: I

(III) C2H5 Propane sultone has the formula:

(IV) H2C-CH2 A preferred procedure is to react the alkylene oxide with the ungelatinized starch, then add the nitrogen containing etherifying agent and the sultone, either sequentially or simultaneously. Thus, ethylene oxide can be added first, followed by the 2-chloroethyldiethylamine hydrochloride, followed by the addition of the propane sultone, or the alkylene oxide can be added to the starch followed by the propane sultone, followed by the addition of the 2-chloroethyldiethylamine hydrochloride, or the 2-chloroethyldiethylamine hydrochloride and the propane sultone can be mixed together in water to form a clear solution before stirring the mixture with a starch slurry after the starch has been pre-reacted with the alkylene oxide.

The basic amino groups are preferably introduced into the starch molecule by using as one of the reactants a tertiary amine or tertiary amine salt containing a reactive group linked to a hydrocarbon group of the amine. The hydrocarbon group or groups of the amine can be alkyl (e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl), aryl (e.g., phenyl, tolyl), aralkyl (e.g., benzyl), or cycloaliphatic (e.g., cyclopentyl, cyclohexyl, or cycloheptyl). The amine can be a monoamine or a polyamine but is preferably a monoamine. It can also be a heterocyclic amine (e.g., piperidine, pyridine). Instead of a tertiary amine or amine salt, a quaternary amine or amine salt can be used. The cationic groups can also be introduced into the molecule by using cyanamide as a reactant. In general, however, from the standpoint of ease of carying out the reac-' tion and of desirable properties in the resultant products, it is preferred to use a water soluble amine or amine salt. The reactive groups of the amine are preferably either halogen (e.g., chloro-, bromo-, etc.) or epoxy. The portion of the amine to which the reactive group is attached is acyclic.

If a tertiary amine is used, the resultant products may be described by the following structural formula:

where X is starch, R is alkylene, preferably having two to six carbon atoms and more specifically two or three carbon atoms, R and R are hydrocarbon, preferably alkyl having one to six carbon atoms and more specifically one to four carbon atoms, R, is alkylene which can be hydrocarbon substituted, preferably having three or four carbon atoms, Y is hydrogen or a salt forming radical, e.g., sodium, potassium, calcium, ammonium, x is 2 to 4, and n, m and p are numerical values where An is an anionic group, preferably sulfonic or sulfonate, but also carboxylic, carboxylate, phosphate or phosphonate; Cat is a cationic group, preferably tertiary amino, tertiary amine salt, quaternary amino or quaternary amine salt but also cyanamide; X is starch, R and R are alkylene, preferably having two to six carbon atoms; as is 2 to 4; m and n are each 0.5 to 6 per 100 anhydroglucose units in X; and p is 10 to 36 per 100 anhydroglucose units in X. The ratio of mm is usually within the range of3:l to 1:3.

The formula does not necessarily depict the complete arrangement of groups within the molecule because the oxyalkylene groups could be linked between the starch molecule and the anionic and/or cationic groups or the anionic and/or cationic groups could be linked between the starch molecule and the hydroxyalkyl groups, or the product could be in the form of mixtures of one or more such structures.

The starch molecule is usually considered to consist of a number of anhydroglucose units (AGU) each having a molecular weight of 162.14. Each AGU has three reactive hydroxyls but one of these reacts more readily than the others.

The term high amylose starch when used herein refers to any starch-or starch fraction containing at least about 50 percent by weight amylose. Exemplary thereof are Nepol amylose (the amylose fraction of corn starch); Superlose (the amylose fraction of potato starch); Amylomaize or A- mylon" (high amylosic cornstarch with about 54 percent amylose); and Amylomaize VII (high amylose corn starch containing about 73.3 percent amylose). Amylomaize VIII with an amylose content of around 85 percent'can also be used. The starchcan be of any'origin, for example, corn, wheat, potato, waxy corn, tapioca, sago or rice. I

While the invention is especially useful when the starch is high amylose starch, it is also useful when the starch is any one of the above enumerated starches other than a high amylose starch, including, but without limitation, regular thin boiling corn starch. V Y

Sultones are intramolecular cyclic esters of hydroxy-sulfonicacids and may be derived both from aliphatic and from aromatic sulfonic acids. Examples of sultones suitable for the present purpose are l,3-propanesultone, l,4-butanesultone, mixtures of isomeric butanesultones (which may be prepared from mixtures of chlorobutanesulfonic acids, obtained by sulfochlorination of l-chlorobutane), benzylsultone and tolylsultone.

Where it is desired to introduce a carboxylic or carboxylate group, sodium chloroacetate or a higher homologue containing two to six carbon atoms is used to furnish the anionic group. The free acids can also be used, e.g., monochloroacetic acid, monobromoacetic acid or monchloropropionic acid but since the reaction is carried out under alkaline conditions the acids will be converted to salts, e.g., sodium, potassium, lithium, calcium, strontium, barium, and/or ammonium. Similarly, acids and salts of phosphorus can be used to introduce phosphate and phosphonate groups.

Examples of nitrogen etherifying agents suitable for in- I troducing cationic groups are: 2-chlorotriethylamine; 2- chlorotriethylamine hydrochloride; 2-chloroethylhydrochloride; 3chloropropyldimethylamine; 3-chloropro- 'pyldimethylamine hydrochloride; 4-chlorobutyidiethylamine; 4-chlorobutyldiethylamine hydrochloride; 2-chloroisopropyldimethylamine; 3-dibutylarnino-l,2-epoxypropane; 2-bromo- S-diethylaminopentane hydrobromide, N-(2,3-epoxypropyl piperidine; N,N-(2,3-epoxypropyl)methyl aniline; 4-chloro-2- butenyltrimethyl ammonium chloride; and 2-hydr0xy-3- chloropropyltrimethylamine chloride. In general, it is preferable to use the salts of the nitrogen esterifying agents, such as, for example, the hydrochlorides and the hydrobromides. Mixtures of nitrogen etherifying agents can be employed. The salts should be selected so as to avoid formation of precipitates. For

example, if calcium, strontium or barium is present, sulfates or phosphates should not be used because insoluble salts, such as calcium sulfate or calcium phosphate, would form. However, sulfates or phosphates of the quaternary amines can be used where sodium, potassium or lithium ions are present.

If the cationic cyanamide groups are introduced into the starch molecule'a cyanamide compound is used, e.g., calcium cyanamide or hydrogen cyanamide (H2NCN).

The alkylene oxide, the anionic reactants and the cationic reactants react with the starch under basic conditions. The reaction can be carried out at ordinary or slightly elevated temperatures below the temperature at which the starch gelatinizes, for example, within the range of 35F. to 135F. In order to obtain uniform'reaction, it is desirable to mix the reactants with a solvent, preferably water. Other solvents, for example, acetone, can be used but they are more expensive and in some cases present problems in recovering the product. The product is ungelatinized and insoluble in water and therefore can be recovered as a granular solid by filtration, washing with water and drying.

The invention will be further illustrated but is not limited by the following examples in which the quantities are stated in parts by weight unless otherwise indicated.

EXAMPLE I a. A slurry of 5,000 grams of ungelatinized Amylomaize VII in 7 liters of water containing 250 grams sodium sulfate (Na SO was prepared. Seventy-five grams of sodium hydroxide were dissolved in 1 liter of water and 250 grams sodium chloride was added. Each mixture was cooled to the ambient temperature (78F and the mixture, containing sodium chloride was stirred into the starch slurry containing the sodium sulfate. a The resultant slurry was'diluted to' 14 liters with water. It had a pH of ll.2 and a conductivity of 640 micromhos at 78F. 300 grams of ethylene oxide and 100 grams of 1,2- propylene oxide were stirred into the mixture. The resultant mixture had apH of l 1.2 and a conductivity of 1,460 mmhos at 80F. After 1 hour, the mixture was divided into two equal parts which were labelled 20.1 and 20.2.

b. In the portion of the mixture labelled 20. l 37.5 grams of 2-chloroethyldiethylamine hydrochloride dissolved in 50 cc'of water were added with stirring at 76F. To the resultant mixture there was gradually added 12.5 grams propane sultone. The mixture was allowed to react for 45 hours at 76F. The pH was then adjusted to 3.5 by adding 130 cc of 6 normal HCl. The product was filtered, reslurried in 10 liters of water; filtered, reslurried in 10 liters of water again; filtered, reslurried in 5 liters of water and the pH adjusted to 3.5. The resultant product was then filtered and dried.

dimethylamine; 2-chloroethyldimethylamine hydrochloride;

3-chloropropyldiethylamine; 3-chloropropyldiethylamine c. To the portion of the mixture labelled 20.2, there was added gradually 250 cc of a 50 percent aqueous solution of H NCN at F. To the resultant mixture there was gradually added 12.5 grams propane sultone. The mixture was allowed to react for 45 hours at 75F It was then processed as in b except in the last slurry 5 grams of aluminum sulfate was added. After 2 hours the last slurry was then filtered and dried.

In Example la the nitrogen content of the product on a dry basis was 0.18. The proportion of Z-ethyldiethylamine hydrochloride was 1.5 percent and the proportion of propane sultone was 0.5 percent.

EXAMPLE II A slurry was prepared by mixing together 50,000 pounds of a starch of the type described in Example 1, 2,500 pounds sodium sulfate, 3,600 pounds sodium chloride, 300 pounds sodium bisulfite, 768 pounds sodium hydroxide, 2,500 pounds ethylene oxide and sufficient water to make 18,500 gallons of slurry. The mixture was allowed to react for 24 hours at approximately 83F. After 24 hours it had a pH of 11.2 and a conductivity of 1,950 mmhos. Then 750 pounds of 2- chloroethyldiethylamine hydrochloride dissolved in gallons of water. (1.5 percent 2-chloroethyldiethylamine hydrochloride on the dry weight of the starch) was poured into the slurry. The slurry had a pH of 1 l and a conductivity of 2,050 mmhos at 82F. Next, 250 pounds propane sultone (0.5 percent on the dry weight of the starch) was dripped into the slurry. The slurry had a pH of 1 1.2 and a conductivity of 5,700 mmhos at 82F.

The mixture was allowed to react for 24 hours at 7682F. after which it has a pH of 11.2 and a conductivity of 7,000 mmhos. The pH was adjusted to 3.5 with 6 N HCl and the slurry filtered, washed and dried. In the slurry just before the drier, a titration of 35 mls of the slurry showed a pH of 3.5 and a conductivity of 570 mmhos at 78 F.

The dry granules analyzed 87.2 percent moisture free solids, 0.15 percent ash on a dry basis, 0.24 percent nitrogen on a dry basis. The NCV viscosity of 48.6 grams was 32.0 seconds. The H of the paste made from these granules was 4.6 and the isoelectric pH was 8.3.

EXAMPLE Ill The procedure was the same as in Example 11 except that 8 percent of a 50 percent aqueous solution of H NCN based on the dry weight of the starch was substituted for the 2- chloroethyldiethylamine hydrochloride.

EXAMPLE IV a. A starch of the type described in Example I was mixed with 5 percent sodium sulfate, 1.5 percent sodium hydroxide, 5 percent sodium chloride, and 7 percent ethylene oxide, with sufficient water to form 3,700 gallons of slurry and the slurry was allowed to react for 48 hours at 78F.

b. One hundred and fifty pounds of calcium hydroxide was slurried in 500 pounds of water and stirred into the slurry prepared as in a. To the resultant mixture was added at 96F. 150 pounds 2-chloroethyldiethylamine hydrochloride dissolved in 500 pounds water. Next 50 pounds of propane sultone was dripped into the slurry at 95F.

After 24 hours reaction at 95100F. the pH of the slurry was adjusted to 4 with 6 N HCl. The solids were washed and filtered twice and then dried. This product had a nitrogen con tent of 0.16 percent on a dry basis. The NCV viscosity of 0.3 anhydroglucose unit was 14 seconds. The isoelectric pH was EXAMPLE V A starch was oxyethylated as described in Example [Va and prepared as a dry product. Five thousand grams of this product was slurried with 8 liters of water and then diluted to 12 liters with water. One hundred and fifty grams of calcium hydroxide in 500 cc of water was stirred into the slurry at a temperature of 84F. One hundred and fifty grams of 2- chloroethyldiethylamine hydrochloride dissolved in 50 cc water was stirred into the mixture and then 50 grams of propane sultone was dripped into the mixture. The mixture was divided into two equal portions.

One portion was allowed to react for 22 hours at an average temperature of 74F. The pH was then adjusted by adding 226 cc of 6 N hydrochloric acid. The solids were filtered, reslurried in 5 liters of water; filtered, reslurried in 5 liters of water; filtered, reslurried in 2.5 liters of water; and then filtered and dried.

The resultant product contained 97 percent solids, 0.20 percent nitrogen on a dry basis, 0.11 percent ash on a dry basis. At a concentration of 0.3 AGU, the NCV viscosity was 9 seconds.

EXAMPLE V1 The procedure was the same as in Example V except that the oxyethylated high amylose starch in proportions of 5,000 grams to 8 liters of water, diluted to 12 liters with water, was divided into two equal portions labelled 13.3 and 13.4.

To the portion 13.3 was added 75 grams calcium hydroxide slurried in 250 ml water, then 75 grams of 2-chloroethyldiethylamine hydrochloride in 25 m1 of water was stirred into the slurry. Thereafter 25 grams of propane sultone were added gradually. The mixture was allowed to stand at 78F. for- 22 hours and the pH was adjusted by adding 212 cc of 6 N hydrochloric acid.

The product was then recovered as described in Example V. This product contained 82.4 percent solids, had a nitrogen content of 0.25 percent on a dry basis, and 58 grams gave an NCV viscosity of 10 seconds.

Portion 13.4 was processed in the same manner as portion 13.3 except that 37.5 grams of calcium hydroxide in 125 cc of water, 37.5 grams of 2-chloroethyldiethylamine hydrochloride in 25 cc of water, and 12.5 grams of propane sultone were used.

The product was recovered in the same manner as in Example V. It contained 87.2 percent solids and a nitrogen content of 0.18 percent, and 55.7 grams had an NCV viscosity of 19 seconds at 72F.

EXAMPLE VIl Five thousand grams of the starch described in Example I were slurried in 7 liters of water and then diluted to 12 liters with water. One hundred and ten grams of calcium hydroxide in 500 cc of water were stirred into the slurry. Five hundred grams of propylene oxide were poured in slowly. After 4 hours, 172 grams of 2-chloroethyldiethylamine hydrochloride in 200 cc of water were stirred into the slurry, and then 31 grams of propane sultone was stirred in slowly. These operations were conducted at temperatures of from 80-84F. The temperature was then adjusted to 130F. and the mixture allowed to react for 17 hours at a temperature of 130-l35F. The pH was then adjusted to 4 with 207 cc of 6 N hydrochloric acid. The slurry was filtered; the solids were reslurried in 10 liters of water; filtered, reslurried in 10 liters of water; filtered and reslurried in 5 liters of water; filtered and dried. The product was an oxypropylated starch containing both basic and acidic groups.

It is advantageous, in accordance with the invention, to provide in the starch slurry prior at addition to the sultone and the etherifying agent, an alkaline earth metal base, such as calcium hydroxide, barium hydroxide or strontium hydroxide. The temperature for reaction of the sultone and the etherifying agent is, in general, room or ambient temperature or temperatures slightly above or below, i.e., a temperature range of about 60F. to F. Where the alkaline earth metal base is employed, the resultant sulfonic acid groups on the sultone will be in whole or in part the alkaline earth metal sulfonate.

The products prepared as previously described were used at their isoelectric point. At this point they contain no charge. However, they can be prepared by separating them without neutralizing with hydrochloric acid or other acidic substances, thereby giving a product having a pH in the range of 10 to 1 1 due to the fact that calcium oxide or hydroxide was present during its preparation. Such a product has a negative charge and is anionic. Hence, it will attract substances which are positively charged, such as basic dyes, cationic melamine-formaldehyde resins, and other cationic resins.

The products can also be prepared so as to have a pH below the isoelectric pH. This can be done, for example, by adding hydrochloric acid until the pH is around 1 and then raising it to about 4 with NaOH or other alkaline substance and separating the resultant product. The product in this case is cationic and when employed in a coating composition, will have an affinity for negatively charged substances, such as acid dyes, acidic resins, e.g., polyester resins, and other acidic resins.

A simple method for determining whether the product is neutral, anionic or cationic is to test an ungelatinized slurry of the product with methylene blue basic dye (Color Index No. 52015) and light green SF yellowish acid dye (Color Index 42095). The cationic products will accept the acid dye. The anionic products will accept the basic dye and no dyeing occurs with either product at the isoelectric point.

The proportions of cationic reactant and anionic reactant used in the process are subject to variation but are preferably in a molar ratio within the range of 1:3 to 3:1, usually around 1:1. An excess of either reactant can be present. As the examples show, the cationic groups and anionic groups do not necessarily react with the starch in the proportions in which they are used in the process. The number of cationic groups normally exceeds the number of anionic groups, the ratio of cationic groups to anionic groups preferably being at least 1.5:], and a preferred range being 1.75:] to 3:1.

SIZING OF TEXTILE FIBERS In the sizing of textile fibers a typical sizing composition can be prepared by mixing 100 pounds of an amphoteric starch prepared in accordance with this invention with 100 gallons of water, preferably with the addition of 5 pounds of petroleum wax, and then heating to the gelatinization temperature. The thread or yarn to be sized, for example, a thread or yearn containing 65 percent polyester fiber (polyethylene glycol terephthalate), and 35 percent cotton fibers, is then sized by passing it through this composition.

In using this sizing composition, the. number of yards of woven material between changes of loom stops can be increased. After weaving, the sizing material can be removed by washing with a detergent water.

The following example is given to illustrate the application of the invention in the sizing of textile fibers.

EXAMPLE Vlll A composition was prepared as described in ExampleVl under 13.4. Two hundred pounds of this composition was mixed with l70-gallons of water and 8 pounds of petroleum wax to form a composition which was then cooked for 1 hour at 210F. The resultant composition had a viscosity of 4.5 seconds (Zahn cup). It was placed in a storage tank and held at a temperature of l90F. A refractometer reading showed that it contained 8 percent solids. This composition was then introduced into a size box for sizing textile yarns and held at a temperature of 180F. A yarn having a denier of and consisting of 50 percent polyester fibers and 50 percent cotton fibers was then passed through the size box and sized at the rate of 55 yards per minute. The yarn was woven into cloth on a loom with excellent results.

In a similar manner, other natural fiber and/or synthetic polymer yarns can be sized with the compositions of the invention, including nylon yarns, polyester yarns, polyacrylonitrile, rayons and yarns of other synthetic fibers or blends thereof with natural fibers, for example, cotton and wool. The invention is especially useful in sizing synthetic fibers which are very difficult to size, such as Nomex nylon.

The compositions of the invention can also be employed in other uses, for example, in the finishing of textiles, in dyeing textiles and paper, in the sizing of paper, in the application of pigments or coatings to cloth and paper, in coating polyolefins, as a coagulating agent in the separation of finely divided mineral particles from ores or water, in sedimentation, and for a wide variety of other purposes.

The term oxyalkylated starch" as used herein refers to a starch which has been reacted with an alkylene oxide. For the purpose of the present invention, the alkylene oxide should contain two to four carbon atoms in the alkylene group. it is believed that the addition of the oxyalkylated groups to the starch molecule makes the starch more reactive, especially 1. An ungelatinized granular oxyalkylated starch containing oxyalkylene groups having two to four carbon atoms and having both cationic and anionic groups connected to the starch molecules through carbon and oxygen, the oxyalkylene groups constituting 10 to 36 groups per anhydroglucose units, and the cationic and anionic groups each constituting 0.5 to 6 groups per 100 anhydroglucose units, said cationic groups being from the class consisting of tertiary amino, tertiary amine salt, quaternary amino, quaternary amine salt and cyanamide and said anionic groups being from the class consisting of sulfonic, sulfonate, carboxylic, carboxylate, phosphate and phosphonate.

2. A starch as claimed in claim 1 having an amylose content of at least 50 percent by weight. g

3. A starch as claimed in claim 1 wherein said oxyalkylene groups are oxyethylene groups.

4. A starch as claimed in claim 1 wherein said oxyalkylene groups are oxypropylene groups. I i

5. A starch as claimed in claim 1 wherein said oxyalkylene groups are both oxypropylene groups and oxyethylene groups.

6. A starch as claimed in claim 1 wherein said anionic groups are from the group consisting of sulfonic and sulfonate.

7. A starch asclaimed in claim 6 wherein said sulfonic acid and said sulfonate contain a radical of the formula R, SO X wherein R; is alkylene of three to four carbons and X is hydrogen, sodium, potassium, lithium, ammonium, calcium, strontium or barium.

8. A starch as claimed in claim 1 wherein said cationic groups contain a radical of the formula R2 wherein R is alkylene of two to six carbons, and R and R are alkyl of l-6 carbons.

9. A starch as claimed in claim 1 wherein said cationic groups are ethylene diethylamine groups connected through carbon of the ethylene group and oxygen to the starch molecule and said anionic groups are R -,-SO X wherein R is alkylene to three to four carbon atoms connected through oxygen of the starch molecule, and X is hydrogen or sodium.

10. A starch as claimed in claim 1 wherein said cationic groups are cyanamide groups.

11. A starch as claimed in claim 1 wherein said cationic groups are quaternary amino in which the hydrocarbon groups attached to the amino nitrogen contain one to six carbon atoms.

12. A product as claimed in claim 1 in which the ratio of cationic groups to anionic groups is within the range of 3:1 to 1:3. I

13. A process for preparing starch containing non-ionic, cationic and anionic groups which comprises reacting an ungelatinized starch in an alkaline aqueous slurry under nongelatinizing conditions first with an alkylene oxide containing two to four carbon atoms, and thereafter with an anionic reactant and a cationic reactant adapted to link the starch through oxygen with a cationic group and an anionic group, the pro- 'Zg;gg UNITED STATES PATENT OFFICE CERTIFICATE OF. CORRECTION iate'nt NO. 3,673,171 Dated June 27, I972 Invent r(s) LEE H. 'ELIZER It is certified that error appears in the above-identified pateht and that said Letters Patent are hereby corrected as shown below:

Under the heading Related U.S. Application Data", after "abandoned.", insert --The terminal portion of this patent which extends beyond November 23', 1988, has been disclai'med.

Signed andeeale'd this 12th day of December 1972;

(SEAL) Attest:

EDWARD M.FLETCHE;R',JR. ROBERT GQTTSCI-IALK Attesting Officer 7 v Commissioner of Patents 

2. A starch as claimed in claim 1 having an amylose content of at least 50 percent by weight.
 3. A starch as claimed in claim 1 wherein said oxyalkylene groups are oxyethylene groups.
 4. A starch as claimed in claim 1 wherein said oxyalkylene groups are oxypropylene groups.
 5. A starch as claimed in claim 1 wherein said oxyalkylene groups are both oxypropylene groups and oxyethylene groups.
 6. A starch as claimed in claim 1 wherein said anionic groups are from the group consisting of sulfonic and sulfonate.
 7. A starch as claimed in claim 6 wherein said sulfonic acid and said sulfonate contain a radical of the formula -R3-SO3X wherein R3 is alkylene of three to four carbons and X is hydrogen, sodium, potassium, lithium, ammonium, calcium, strontium or barium.
 8. A starch as claimed in claim 1 wherein said cationic groups contain a radical of the formula wherein R is alkylene of two to six carbons, and R1 and R2 aRe alkyl of 1-6 carbons.
 9. A starch as claimed in claim 1 wherein said cationic groups are ethylene diethylamine groups connected through carbon of the ethylene group and oxygen to the starch molecule and said anionic groups are -R3-SO3X wherein R3 is alkylene to three to four carbon atoms connected through oxygen of the starch molecule, and X is hydrogen or sodium.
 10. A starch as claimed in claim 1 wherein said cationic groups are cyanamide groups.
 11. A starch as claimed in claim 1 wherein said cationic groups are quaternary amino in which the hydrocarbon groups attached to the amino nitrogen contain one to six carbon atoms.
 12. A product as claimed in claim 1 in which the ratio of cationic groups to anionic groups is within the range of 3:1 to 1:3.
 13. A process for preparing starch containing non-ionic, cationic and anionic groups which comprises reacting an ungelatinized starch in an alkaline aqueous slurry under non-gelatinizing conditions first with an alkylene oxide containing two to four carbon atoms, and thereafter with an anionic reactant and a cationic reactant adapted to link the starch through oxygen with a cationic group and an anionic group, the proportions being sufficient to introduce into the starch molecule 10 to 36 alkylene groups, 0.5 to six cationic groups and 0.5 to six anionic groups per 100 anhydroglucose units of said starch, said cationic groups being from the class consisting of tertiary amino, tertiary amine salt, quaternary amino, quaternary amine salt and cyanamide and said anionic groups being from the class consisting of sulfonic, sulfonate, carboxylic, carboxylate, phosphate and phosphonate. 